LOS ALAMOS, N.M. — The U.S. Energy Department is still uncertain about the extent of contamination from a massive plume of chromium that resulted from decades of poor waste management at Los Alamos National Laboratory.

Doug Hintze with the Energy Department’s environmental management field office in Los Alamos told state lawmakers during a recent hearing that cancer-causing chromium and other chemicals have continued to seep from the soil in Mortandad Canyon into the groundwater.

Chromium was detected at concentrations five times the state limit in July in a newly drilled well outside the perimeter of the plume, The Santa Fe New Mexican reported (http://bit.ly/2yzIJ7f ).

Hintze said the revelation was not surprising and that the plume’s shape is different than what was initially shown on the lab’s charts and maps.

“It is very difficult to show how quickly it’s migrating,” he said, “but we do believe it is migrating and growing.”

Hintze’s testimony prompted lawmakers to say they would appeal to New Mexico’s congressional delegates and request more federal funds to expedite cleanup. They also called for the lab to address the issue more aggressively because the plume has been encroaching upon a regional aquifer.

The lab had intended to use the tainted well, drilled earlier this year, to inject clean water into areas at the edge of the plume in an effort to contain the contamination. Now it appears that use of the well would risk spreading the contamination.

The plume is believed to be a mile (1.6 kilometers) long, a half-mile (0.8 kilometers) wide and about 100 feet (30 meters) thick. It is bordered on the south by San Ildefonso Pueblo land.

Hintze said the plume is migrating south and southeast.

The Energy Department has been drilling a number of wells in the area to monitor chromium levels. So far, there are fewer than two dozen monitoring wells, which Hintze said cost about $3 million each to drill.

A 2016 estimate said cleanup was expected to cost $180 million and would take several decades. Part of the process would involve injecting a form of molasses into the plume to convert highly carcinogenic hexavalent chromium, chromium-6, into less toxic chromium-3.

Lab cleanup of hazardous waste generated before 1999 is governed by an agreement, or consent order, between state and federal officials. That order was overhauled last year after the lab failed to meet deadlines set under a previous agreement.

Critics say the order fails to set deadlines for cleanup and does not hold the federal government sufficiently accountable for ensuring the work is completed.

Sen. Jeff Steinborn, a Las Cruces Democrat who chairs the legislative Radioactive and Hazardous Materials Committee, said he was interested in exploring whether the state could renegotiate the cleanup order after a new governor takes office in 2019.


Information from: The Santa Fe New Mexican, http://www.sfnewmexican.com